A fixed charge is a flat fee your customer's utility adds to every bill, and a minimum bill is the least they pay in a month. They're a common reason a customer still has a utility bill after going solar. This article explains how they differ, how Aurora applies them, and where to find them.
In this article:
- How fixed charges and minimum bills differ
- How Aurora applies them
- Where to find them in Aurora
- Key considerations
- FAQ
- Related articles
How fixed charges and minimum bills differ
A fixed charge is a flat fee, sometimes called a customer charge or basic charge, that customers pay every month regardless of how much energy they use.
A minimum bill is the least a customer pays for a month. If the month's charges come to less, the utility bills the minimum instead. Some utilities set the minimum bill equal to the fixed charge, some set a different amount, and others have none.
For example, with a $10 monthly fixed charge, energy at $0.15 per kWh, and a $20 minimum bill:
| Month | Energy charges | Fixed charge | Charges before the minimum | Bill |
|---|---|---|---|---|
| Uses 150 kWh | $22.50 | $10.00 | $32.50 | $32.50 |
| Uses 50 kWh | $7.50 | $10.00 | $17.50 | $20.00 — the minimum bill applies |
| Solar credits cover all energy charges | $0.00 | $10.00 | $10.00 | $20.00 — the minimum bill applies |
The third month assumes solar credits can't reduce the fixed charge, which is Aurora's default.
How Aurora applies them
- Fixed charge. Aurora adds the rate's fixed charge to every monthly bill, before and after solar. On standard rates (any rate that isn't a custom rate), Aurora combines all the utility's monthly charges and riders (add-on charges) into this one fixed charge. Aurora multiplies a per-day fixed charge by 30.5, the average number of days in a month.
- Solar credits. By default, solar credits reduce energy charges but not the fixed charge. Some utilities let credits reduce the fixed charge too. On standard rates, Aurora's utility team turns this on for each utility or rate. On custom rates, an admin turns on Apply solar credits to fixed charges.
- Minimum bill. If a month's energy charges plus the fixed charge come to less than the minimum bill, Aurora charges the minimum bill. This applies month by month, even with annual billing. On a custom rate with Apply solar credits to fixed charges turned on, credits can bring the bill to $0, even when the rate has a minimum bill.
- Compensation payment. When this post-solar rate setting is Cash, Aurora applies net surplus compensation as a credit in the true-up month. That can reduce the month's bill, including the fixed charge.
Where to find them in Aurora
Rate panel
In your project, go to Energy usage. Under Grid electricity, click View rate next to Current rate or Future rate. The Import rate tab shows the rate's Fixed charge, Minimum bill, and Billing frequency. The panel title calls these the pre-solar and post-solar rates.
In Sales Mode, the same rates are on the Energy usage tab of Project details.
Sales Mode proposal
The before-and-after cost comparison shows Fixed costs under Without PV and With PV. Each is the average monthly fixed charge your customer pays in year 1, after any cash compensation payment.
Key considerations
- You can't change the Fixed charge or Minimum bill on a standard rate, even as an admin. If they don't match your customer's bill, an admin can create a custom rate with the correct values. For steps, see Creating custom utility rates
- Only admins can create or edit custom rates. Non-admins can view them in Database.
- Changing a custom rate doesn't update existing designs. To apply the change, select a different rate, then reselect the custom rate.
- Pre-solar and post-solar rates can have different fixed charges, so check both.
- Aurora doesn't include taxes, so your customer's actual bill can be higher.
- Aurora can't model some rate structures, such as minimum bills that apply only under certain conditions or fixed charges that increase with usage.
FAQ
Why does my customer still have a utility bill with 100% offset?
By default, solar credits don't reduce the fixed charge, so it stays on every bill, and a minimum bill can raise low months. For other causes, see How can I improve savings on my project?
Why is the With PV fixed cost in the proposal lower than the rate's fixed charge?
Fixed costs is the average monthly fixed charge for year 1. When Compensation payment is Cash, Aurora applies the payment in the true-up month, which can reduce that month's fixed charge and lower the average.
Can solar credits pay the fixed charge?
Only on rates that allow it. On custom rates, admins control this with Apply solar credits to fixed charges. On standard rates, Aurora's utility team sets it, and the rate panel doesn't show the setting.
The fixed charge doesn't match my customer's bill. How do I fix it?
You can't edit the fixed charge on a standard rate. Ask an admin to create a custom rate using the charges on your customer's bill.